XML 189 R161.htm IDEA: XBRL DOCUMENT
v3.20.4

Exchangeable Securities - Option To Exchange (Details) - Option to exchange - CAD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Disclosure of detailed information about borrowings [line items] |  |
Fair value | $ 0 | $ 0
Minimum |  |
Disclosure of detailed information about borrowings [line items] |  |
Sensitivity percentage | 0 | 0
Maximum |  |
Disclosure of detailed information about borrowings [line items] |  |
Sensitivity percentage | $ (33) | $ (27)

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfDetailedInformationAboutBorrowingsLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Sensitivity Analysis For Option To Exchange Securities For Ownership, Reasonably Possible Change In Risk Variable, Amount + References No definition available. + Details
Name: | tac_SensitivityAnalysisForOptionToExchangeSecuritiesForOwnershipReasonablyPossibleChangeInRiskVariableAmount
Namespace Prefix: | tac_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Sensitivity Analysis For Option To Exchange Securities For Ownership, Reasonably Possible Change In Risk Variable, Percent + References No definition available. + Details
Name: | tac_SensitivityAnalysisForOptionToExchangeSecuritiesForOwnershipReasonablyPossibleChangeInRiskVariablePercent
Namespace Prefix: | tac_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ifrs-full_TypesOfRisksAxis=tac_OptionToExchangeRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |